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 * Copyright (c) 2000, 2013, Oracle and/or its affiliates. All rights reserved.
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
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package javax.management.openmbean;

// java import
//

import java.util.ArrayList;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

// jmx import
//


/**
 * The <code>TabularType</code> class is the <i> open type</i> class
 * whose instances describe the types of {@link TabularData TabularData} values.
 *
 * @since 1.5
 */
public class TabularType extends OpenType<TabularData> {

  /* Serial version */
  static final long serialVersionUID = 6554071860220659261L;


  /**
   * @serial The composite type of rows
   */
  private CompositeType rowType;

  /**
   * @serial The items used to index each row element, kept in the order the user gave This is an
   * unmodifiable {@link ArrayList}
   */
  private List<String> indexNames;


  private transient Integer myHashCode = null; // As this instance is immutable, these two values
  private transient String myToString = null; // need only be calculated once.


    /* *** Constructor *** */

  /**
   * Constructs a <code>TabularType</code> instance, checking for the validity of the given
   * parameters. The validity constraints are described below for each parameter. <p> The Java class
   * name of tabular data values this tabular type represents (ie the class name returned by the
   * {@link OpenType#getClassName() getClassName} method) is set to the string value returned by
   * <code>TabularData.class.getName()</code>. <p>
   *
   * @param typeName The name given to the tabular type this instance represents; cannot be a null
   * or empty string. <br>&nbsp;
   * @param description The human readable description of the tabular type this instance represents;
   * cannot be a null or empty string. <br>&nbsp;
   * @param rowType The type of the row elements of tabular data values described by this tabular
   * type instance; cannot be null. <br>&nbsp;
   * @param indexNames The names of the items the values of which are used to uniquely index each
   * row element in the tabular data values described by this tabular type instance; cannot be null
   * or empty. Each element should be an item name defined in <var>rowType</var> (no null or empty
   * string allowed). It is important to note that the <b>order</b> of the item names in
   * <var>indexNames</var> is used by the methods {@link TabularData#get(java.lang.Object[]) get}
   * and {@link TabularData#remove(java.lang.Object[]) remove} of class <code>TabularData</code> to
   * match their array of values parameter to items. <br>&nbsp;
   * @throws IllegalArgumentException if <var>rowType</var> is null, or <var>indexNames</var> is a
   * null or empty array, or an element in <var>indexNames</var> is a null or empty string, or
   * <var>typeName</var> or <var>description</var> is a null or empty string. <br>&nbsp;
   * @throws OpenDataException if an element's value of <var>indexNames</var> is not an item name
   * defined in <var>rowType</var>.
   */
  public TabularType(String typeName,
      String description,
      CompositeType rowType,
      String[] indexNames) throws OpenDataException {

    // Check and initialize state defined by parent.
    //
    super(TabularData.class.getName(), typeName, description, false);

    // Check rowType is not null
    //
    if (rowType == null) {
      throw new IllegalArgumentException("Argument rowType cannot be null.");
    }

    // Check indexNames is neither null nor empty and does not contain any null element or empty string
    //
    checkForNullElement(indexNames, "indexNames");
    checkForEmptyString(indexNames, "indexNames");

    // Check all indexNames values are valid item names for rowType
    //
    for (int i = 0; i < indexNames.length; i++) {
      if (!rowType.containsKey(indexNames[i])) {
        throw new OpenDataException(
            "Argument's element value indexNames[" + i + "]=\"" + indexNames[i] +
                "\" is not a valid item name for rowType.");
      }
    }

    // initialize rowType
    //
    this.rowType = rowType;

    // initialize indexNames (copy content so that subsequent
    // modifs to the array referenced by the indexNames parameter
    // have no impact)
    //
    List<String> tmpList = new ArrayList<String>(indexNames.length + 1);
    for (int i = 0; i < indexNames.length; i++) {
      tmpList.add(indexNames[i]);
    }
    this.indexNames = Collections.unmodifiableList(tmpList);
  }

  /**
   * Checks that Object[] arg is neither null nor empty (ie length==0)
   * and that it does not contain any null element.
   */
  private static void checkForNullElement(Object[] arg, String argName) {
    if ((arg == null) || (arg.length == 0)) {
      throw new IllegalArgumentException("Argument " + argName + "[] cannot be null or empty.");
    }
    for (int i = 0; i < arg.length; i++) {
      if (arg[i] == null) {
        throw new IllegalArgumentException(
            "Argument's element " + argName + "[" + i + "] cannot be null.");
      }
    }
  }

  /**
   * Checks that String[] does not contain any empty (or blank characters only) string.
   */
  private static void checkForEmptyString(String[] arg, String argName) {
    for (int i = 0; i < arg.length; i++) {
      if (arg[i].trim().equals("")) {
        throw new IllegalArgumentException(
            "Argument's element " + argName + "[" + i + "] cannot be an empty string.");
      }
    }
  }


    /* *** Tabular type specific information methods *** */

  /**
   * Returns the type of the row elements of tabular data values
   * described by this <code>TabularType</code> instance.
   *
   * @return the type of each row.
   */
  public CompositeType getRowType() {

    return rowType;
  }

  /**
   * <p>Returns, in the same order as was given to this instance's
   * constructor, an unmodifiable List of the names of the items the
   * values of which are used to uniquely index each row element of
   * tabular data values described by this <code>TabularType</code>
   * instance.</p>
   *
   * @return a List of String representing the names of the index items.
   */
  public List<String> getIndexNames() {

    return indexNames;
  }

  /**
   * Tests whether <var>obj</var> is a value which could be
   * described by this <code>TabularType</code> instance.
   *
   * <p>If <var>obj</var> is null or is not an instance of
   * <code>javax.management.openmbean.TabularData</code>,
   * <code>isValue</code> returns <code>false</code>.</p>
   *
   * <p>If <var>obj</var> is an instance of
   * <code>javax.management.openmbean.TabularData</code>, say {@code
   * td}, the result is true if this {@code TabularType} is
   * <em>assignable from</em> {@link TabularData#getTabularType()
   * td.getTabularType()}, as defined in {@link
   * CompositeType#isValue CompositeType.isValue}.</p>
   *
   * @param obj the value whose open type is to be tested for compatibility with this
   * <code>TabularType</code> instance.
   * @return <code>true</code> if <var>obj</var> is a value for this tabular type,
   * <code>false</code> otherwise.
   */
  public boolean isValue(Object obj) {

    // if obj is null or not a TabularData, return false
    //
    if (!(obj instanceof TabularData)) {
      return false;
    }

    // if obj is not a TabularData, return false
    //
    TabularData value = (TabularData) obj;
    TabularType valueType = value.getTabularType();
    return isAssignableFrom(valueType);
  }

  @Override
  boolean isAssignableFrom(OpenType<?> ot) {
    if (!(ot instanceof TabularType)) {
      return false;
    }
    TabularType tt = (TabularType) ot;
    if (!getTypeName().equals(tt.getTypeName()) ||
        !getIndexNames().equals(tt.getIndexNames())) {
      return false;
    }
    return getRowType().isAssignableFrom(tt.getRowType());
  }


    /* *** Methods overriden from class Object *** */

  /**
   * Compares the specified <code>obj</code> parameter with this <code>TabularType</code> instance
   * for equality. <p> Two <code>TabularType</code> instances are equal if and only if all of the
   * following statements are true: <ul> <li>their type names are equal</li> <li>their row types are
   * equal</li> <li>they use the same index names, in the same order</li> </ul> <br>&nbsp;
   *
   * @param obj the object to be compared for equality with this <code>TabularType</code> instance;
   * if <var>obj</var> is <code>null</code>, <code>equals</code> returns <code>false</code>.
   * @return <code>true</code> if the specified object is equal to this <code>TabularType</code>
   * instance.
   */
  public boolean equals(Object obj) {

    // if obj is null, return false
    //
    if (obj == null) {
      return false;
    }

    // if obj is not a TabularType, return false
    //
    TabularType other;
    try {
      other = (TabularType) obj;
    } catch (ClassCastException e) {
      return false;
    }

    // Now, really test for equality between this TabularType instance and the other:
    //

    // their names should be equal
    if (!this.getTypeName().equals(other.getTypeName())) {
      return false;
    }

    // their row types should be equal
    if (!this.rowType.equals(other.rowType)) {
      return false;
    }

    // their index names should be equal and in the same order (ensured by List.equals())
    if (!this.indexNames.equals(other.indexNames)) {
      return false;
    }

    // All tests for equality were successfull
    //
    return true;
  }

  /**
   * Returns the hash code value for this <code>TabularType</code> instance. <p> The hash code of a
   * <code>TabularType</code> instance is the sum of the hash codes of all elements of information
   * used in <code>equals</code> comparisons (ie: name, row type, index names). This ensures that
   * <code> t1.equals(t2) </code> implies that <code> t1.hashCode()==t2.hashCode() </code> for any
   * two <code>TabularType</code> instances <code>t1</code> and <code>t2</code>, as required by the
   * general contract of the method {@link Object#hashCode() Object.hashCode()}. <p> As
   * <code>TabularType</code> instances are immutable, the hash code for this instance is calculated
   * once, on the first call to <code>hashCode</code>, and then the same value is returned for
   * subsequent calls.
   *
   * @return the hash code value for this <code>TabularType</code> instance
   */
  public int hashCode() {

    // Calculate the hash code value if it has not yet been done (ie 1st call to hashCode())
    //
    if (myHashCode == null) {
      int value = 0;
      value += this.getTypeName().hashCode();
      value += this.rowType.hashCode();
      for (String index : indexNames) {
        value += index.hashCode();
      }
      myHashCode = Integer.valueOf(value);
    }

    // return always the same hash code for this instance (immutable)
    //
    return myHashCode.intValue();
  }

  /**
   * Returns a string representation of this <code>TabularType</code> instance. <p> The string
   * representation consists of the name of this class (ie <code>javax.management.openmbean.TabularType</code>),
   * the type name for this instance, the row type string representation of this instance, and the
   * index names of this instance. <p> As <code>TabularType</code> instances are immutable, the
   * string representation for this instance is calculated once, on the first call to
   * <code>toString</code>, and then the same value is returned for subsequent calls.
   *
   * @return a string representation of this <code>TabularType</code> instance
   */
  public String toString() {

    // Calculate the string representation if it has not yet been done (ie 1st call to toString())
    //
    if (myToString == null) {
      final StringBuilder result = new StringBuilder()
          .append(this.getClass().getName())
          .append("(name=")
          .append(getTypeName())
          .append(",rowType=")
          .append(rowType.toString())
          .append(",indexNames=(");
      String sep = "";
      for (String index : indexNames) {
        result.append(sep).append(index);
        sep = ",";
      }
      result.append("))");
      myToString = result.toString();
    }

    // return always the same string representation for this instance (immutable)
    //
    return myToString;
  }

}
